Voice Coil Bobbin Reinforcement for Vibration Loss Reduction
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Solution Overview
Problem
Conventional voice coil bobbins for full-range and mid/treble speakers face challenges in being lightweight, strong, and minimizing vibration loss while maintaining structural integrity, as they either become too heavy with metallic layers or structurally weakened when thinned.
Innovation Solution
A voice coil with a cylindrical bobbin made of an isotropic material, such as paper or aramid fiber, reinforced with strip-shaped members made of materials like aluminum, copper, or titanium, which have faster sound propagation speeds, laminated on the outer surface to enhance mechanical strength and reduce vibration loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metallic layer is deposited on the entire surface of the resin film base to strengthen the bobbin, then the strength is improved, but the weight increases making it unsuitable for full-range and mid/treble speakers
Solution Approach 1:
The patent applies reinforcement members only to specific portions of the bobbin where structural support is needed, rather than covering the entire surface. This localized reinforcement approach provides necessary strength while minimizing weight addition, making it suitable for full-range and mid/treble speakers where weight sensitivity is critical.
Solution Approach 2:
The patent combines different materials with complementary properties: a resin film base providing lightweight structure and reinforcement members (such as metal strips or high-strength fibers) providing localized strength. This composite structure achieves the desired strength-to-weight ratio for sensitive speaker applications.
2Weight of moving object
If the thickness of the bobbin is reduced to decrease weight, then the weight is reduced, but the structural strength is weakened causing treble resonance and vibration loss
Solution Approach 1:
The patent compensates for reduced overall thickness by adding reinforcement members at critical locations where structural support is most needed. This allows the bobbin to maintain thin overall dimensions for low weight while having localized reinforced zones that prevent treble resonance and vibration loss.
Solution Approach 2:
The patent uses composite construction with a thin resin film base combined with reinforcement members to achieve high strength-to-weight ratio. The thin base provides minimal weight while the reinforcement members provide the necessary structural integrity to prevent vibration-related issues.
3Ease of manufacture
If conventional materials are used for the voice coil bobbin, then ease of manufacture is maintained, but no single material achieves high propagation velocity, lightweight, strength, and low vibration loss simultaneously
Solution Approach 1:
The patent combines materials with different acoustic properties: the resin film base provides ease of manufacture and lightweight characteristics, while the reinforcement members provide high sound propagation velocity and structural strength. This composite approach achieves multiple performance targets that no single conventional material can meet alone.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a voice coil that is lightweight, strong, and capable of reducing vibration loss, allowing for faithful sound reproduction by enhancing the mechanical strength of the unwound portion and improving sound propagation velocity.
Implementation Method 1
a plurality of reinforcement members formed of a material having a propagation speed faster than the first material and provided on the outer circumferential surface of the cylindrical bobbin
Data Source
AI summary
A voice coil includes a cylindrical bobbin formed of a first material; a coil which surrounds on an outer circumferential surface of the bobbin; and a plurality of reinforcement members formed of a material having a propagation speed faster than the first material and provided on the outer circumferential surface of the cylindrical bobbin.